


What's Mine is Mine

by MintEyedDemon



Category: Shall We Date?: Obey Me!
Genre: F/M, Fluff and Smut, Gender-Neutral Pronouns, M-Mammon is tsundere boy, Plot What Plot/Porn Without Plot, Sex Toys, Smut
Language: English
Status: Completed
Published: 2020-08-02
Updated: 2020-08-02
Packaged: 2021-03-06 02:53:34
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,662
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25676146
Author URL: https://archiveofourown.org/users/MintEyedDemon/pseuds/MintEyedDemon
Summary: This takes place during Ch.4A-C, where Mammon is going through your things, but he ends up finding something much more personal!First time writing for this fandom, so please be gentle. I may not have gotten the characterizations correct yet!
Relationships: Main Character & Mammon (Shall We Date?: Obey Me!), Main Character/Mammon (Shall We Date?: Obey Me!), Mammon (Shall We Date?: Obey Me!) & Reader, Mammon (Shall We Date?: Obey Me!)/Reader
Comments: 7
Kudos: 340





	What's Mine is Mine

"What's (Y/N)'s is mine, and what's mine is miiine!~"

Mammon hummed cheerfully to himself as he went through several of your drawers and your closet, searching for anything valuable he could, at least what he told himself he could, pawn off for Grimm. He found mostly casual clothing and several uniforms, nothing that looked really worth a lot of money; until he happened upon a box hidden in your desk.

"Oh? Could this have money in it?" He gave the box a slight sniff. "Nah, doesn't smell like money. Maybe jewelry, or a bank card!?" When he finally opened it, he gave a small scoff of annoyance. "Nope, just chocolate and sweets, feh."

A larger hand took the box from his quickly, and he turned with a small start to see his younger brother Beel, who was now munching on (Y/N)'s sweets. "I'll take these."

"Of course, if food is around, you're bound to show up, aren'tcha Beel? Guaranteed," Mammon mumbled, before turning around to continue his search for goods in your room.

"What are you even looking for? You know this is (Y/N)'s room, right?" Beel asked around a mouthful of cookie. Mammon continued to tear through your other drawers, laughing at his brother's question. "Of course I know! I'm looking for anything I can make some money off of. I can't just ask (Y/N) for money, so instead I have to look through their things while they are gone. I am sure they have something worth some money in here somewhere. And since I am stuck looking after them, I feel I have a right to take what I want from them!"

Beel gave a slight roll of his eyes, continuing to munch on the chocolate pieces in the box. "You know you won't actually sell their things, Mammon. No matter what you say, you couldn't bring yourself to  _ actually _ do it."

Mammon looked at Beel with as deep a glare as he could muster. "Don't pretend ya know what I will and won't do! You're talking to THE Mammon, ya know! You bet I would sell their things, hell, I would even sell them if I knew it would turn a good profit! I don't even care about how they feel, THE Mammon doesn't care about any humans! (Y/N) isn't special to me in any shape or form!"

"I didn't mention anything about caring about them  _ or _ them being special, Mammon," Beel mumbled around another mouthful, "besides, even if you did take any of their things, you made a pact with (Y/N). All they would have to do is tell you to bring their things back and you would have to do it. You know that."

Mammom turned away from his brother, practically burying himself in digging through another drawer to hide the blush on his face. "It's not like they would know it was me! I could get away with it no problem!" He stopped suddenly when he noticed a black silky bag at the back of the drawer, and he pulled it forward. "What do we have here?" he whispered to himself, opening the bag. He froze in place when he realized what the object was, closed the bag back up and shoved it back into its spot before his brother could notice.

Thankfully, Beel was too busy shaking the box over his mouth to free up the crumbs from it to notice him. "Just admit it," he finally said with a sigh, tossing the box over his shoulder once it was completely empty. "The truth is you like your human so much that you can't handle but go through their things like this. You aren't going to sell any of this stuff."

Mammon turned on him quickly, flustered. "Are you joking!? Me, care about a human!? I don't care about some stupid human! All they are is demon food, nothing more than bugs to be stepped on! I don't care about anything this damn human does o-or owns or anything! I don't care one bit!"

Beel simply laughed at his mess of a brother. "You could have fooled me, Mammon. Look at how riled up you are getting. So desperate to seem like you don't care when you are practically screaming how much you do. It's kind of cute, actually." He placed a hand on his stomach when a loud rumble came from it, frowning. "Ugh, I'm gonna go to the kitchen and find something more to eat. Try not to destroy their room too bad, will you?"

With that, Beel left the room, leaving Mammon a flustered mess, now staring at the drawer where the silk bag was hidden. His hands shook as he reopened the drawer, and pulled the silky bag out once more. When he opened it again, he flushed instantly, realizing that what he was staring at was in fact a black dildo, that could only belong to (Y/N). Why would they own something like this and leave it where he could so easily find it!? Oh, right...they were hiding it in their drawer, and he happened to find it. Still, would they really need something like this? Couldn't they just...ask him for help, in situations like that? Right. He was just their guard demon right now, so chances were they wouldn't ask him about something like that. Besides, he didn't care about them! He didn't care at all about them!

...Right?

Well...maybe he was more curious than anything right now so...he could ask them about it when they got home. The real issue now was, how to bring it up in conversation.

***

When you finally arrived home from class, you could hear movement coming from inside your room. Cautiously, you opened the door and peered in, only to find Mammon pacing in your room, holding something in his hands and mumbling to himself. You decided to step in and walked up to the pacing demon, placing a hand on his arm to draw his attention.

"Mammon, what are you--!?"

He acted as if you struck him, jumping a foot away from you, hiding the black bag behind his back. "(Y/N)! Wh-when did you get home? Why didn't you knock before coming in!?"

You flushed deeply when you realized what he was holding, stepping closer to him to try and take it from him. "Mammon this is my room! I don't need to knock, and you shouldn't be in here going through my things! Give that back to me!"

He moved before you could make contact with him, holding the bag above his head and out of your reach. "Not until you tell me why you have it! Where did you get it? Did Asmo give it to you or something? It looks like something he would own! Why do you have something like this, (Y/N)!?"

Your flush only deepened and swatted at his chest over and over until he curled in on himself a bit, giving you a chance to reach up and grab the bag from his hand. "Hey, give that back! You didn't answer my question!" he hollered, lunging for you.

You moved out of his reach this time and ran towards your door, swinging it open and pointing out. "Leave, now! I don't need to explain to you why I own...certain things. Now go!"

Mammon frowned, moving towards the door, but instead of leaving, closed it and locked it. He turned on you and seemed to tower over you, hands on his hips in annoyance. "I have a right to know what  _ my _ human owns, so I went through your things, big whoop. I found this sex toy, and I want to know why you own it, so I would answer me if I was you before I decide to  _ eat you _ . So, answer me, (Y/N)!"

You swallowed thickly at his threat, his voice getting lower and turning into a growl as he spoke. You clutched the bag to your chest, stepping back a bit from him until finally giving a deep sigh of defeat. "I got it because I've been feeling...needy, okay? Asmo told me of a place in town I could get one, no he didn't help me get it," you added when you noticed the glare on his face, "but I just...wanted something to take care of myself with. That's it. Happy now?"

You felt shame wash over your body at being caught with your toy, but you finally gave this damn demon the answer he was hounding for. You were silently hoping that would be good enough, that he would be satisfied with your answer and finally leave you alone; but instead, he stepped closer, forcing you to back up against the wall of your room and tower over you once more. He looked down at you with hunger in his eyes; a different kind you hadn't seen before. He was even slightly pouting at you.

"Ya know, (Y/N), if you really needed help in that department ya coulda just asked me instead. I, ugh, I don't mind...taking care of ya if you really need it. Hell, you should be flattered I'd want to take care of you like that! The Great Mammon doesn't offer things like that to just anyone, ya know."

A deep blush took over his cheeks and you felt your heart flutter in your chest. "I...I didn't think you would be interested in me like that…"

He flared suddenly. "Are you dense!? Humans really are so dumb! I--" He stopped himself, taking on his cool facade once more before giving too much away. "Maybe I am, maybe I'm not. But right now, I am offering to take care of you, so if I were you, I would jump on the opportunity. Besides," he took the bag from your hands quickly, "I'm curious as to how you use this thing too. So why not let me, ya know, watch?"

You squeaked, pulling the bag away from him once more and darting out of his shadow against the wall. "Watch me!? You're joking! Mammon, this is all so sudden, I couldn't let you do any of that!"

He was on you once more, and he walked you back towards your bed, pushing you back on it as he hovered above you. He gently pushed your bangs from your forehead, and gave you a smirk. "I don't see what the big deal is. You're needy, and I'm willing to help the poor human out. The least you can do for me first is show me how you play with your toy. It's not that big of a deal, is it?"

You swallowed the lump forming in your throat, looking away from his face and around your room for any form of escape, until he grabbed your chin and forced you to look at him once more. "C'mon (Y/N), dontcha think it'll be fun to do with your sweet and amazing Mammon?" He leaned his head forward and placed a deep kiss against your lips. You instantly melted into his touch, giving a soft sigh as he deepened the kiss, nipping at your lip for entry into your mouth. He pulled away all too soon, making you whimper at the contact.

"So, is that a yes?" he teased, and you flushed deeply, but rolled your eyes at him.

"Okay...I'll do it."

He grinned widely at you, and shifted on your bed to give you space to finally move. He sat at the edge and watched your every move intently as you stood to strip off your uniform, leaving you in your green shirt and underwear. You went to your drawer for a moment to grab a little bottle from it and returned to your spot on the bed, blushing furiously at the excited look in Mammon's eyes. You finally removed your underwear and wanted to hide when you saw his mouth slack open from staring at you. It took everything in him to not dive in on you while you spread your legs to use your lubricant on your folds. When you finally pressed the head of the toy to your entrance he felt his breath catch in his chest when you whined at the pressure of it against your clit. He watched you rub it against yourself, your eyes fluttered closed, and finally when you pushed it in, he let out a small moan along with yours.

You let it sink deep into you, pulling it out slowly and pressing it back in just as slow. You were embarrassed to be on display like this but at the same time, excited it was Mammon watching you. You let your eyes open for a moment and let out a small squeak when you noticed he was staring fully at your hands working on yourself.

Ever the impatient demon, he scooted closer to you, placing his hand on yours that was moving the toy in and out of your core. "Let me take over, babe," he whispered to you, taking the toy and pressing it fully inside you. The sudden fullness made you gasp and buck against the toy, and he smirked down at you, pulling it all the way out only to slam it back into you. You didn't expect him to want to participate; but it was the Avatar of Greed here with you. He was bound to want to take over at some point.

"M-Mammon!" His name came out in a gasp when he hit a particularly sensitive spot, and he realized he desperately wanted to hear you say his name again. He used the toy on you a bit longer but soon pulled it from you and flung it across the room. You cried out at the emptiness and glared at him for a moment before realizing what he was doing.

"Fuck, I can't hold back anymore," he grumbled, scrambling to his feet to discard his clothing. He climbed atop you, and you bit your lip when you saw his full length against your folds. He looked clearly bigger than your toy and you couldn't help but rub against him as he pressed down on you to slick up his shaft. "Better be ready, babe, cause I plan on filling you to the brim," he growled against your lips before kissing you deeply and delving his cock deep inside you.

He allowed you a few seconds to adjust, before pounding into you over and over. You could feel the tip of his cock flush against your cervix time and time again, making you see stars with each thrust. He only sped up his thrusts when you began to tighten around him, your nails digging into his back as he did so. His name tumbled from your lips over and over like a mantra, and he thrilled in hearing them, becoming harder inside you. Finally your vision went white and your walls tightened around his cock, milking him until he finally came along with you, filling you up with his seed.

He let himself collapse on top of you, burying his face in your hair and inhaling deeply. You could feel him still buried deep inside you and you let out a high moan when he reluctantly pulled out. He rolled you both onto your sides, pulling you into his arms tightly as he nuzzled your hair.

"You don't need that stupid toy," he grumbled into your hair. "See? I'm far better than that hunk of rubber. If ever you feel needy like this again, just call me, and if I have the time, I'll come take care of you. Maybe," he teased, going back to his usual self.

"Well what if you don't have time? I need it just in case--"

"No!" he growled, hugging you possessively. "I will always make time for you, (Y/N)."

**Author's Note:**

> I am sorry this kind of sucked, lol. But I love Mammon a lot, the tsundere brat lol


End file.
